Conduit forming apparatus and process



Nov. 8, 1932. J. F. MURRAY coNDU1T- FORMING APPARATUS AND PRocEss Filed Aug. 17, 1928 Patented Nov. 8, 1932 Joniv r. nennen 0F BROOKLYN, NEWYORK, AssIGNo Tol MET-RoOLITANpEVICE coNpUnpFoRiyrING AnPARA'nus AND Pnoonss nppncauon'nd nue-lg 17,192.8, serial n.0. @geen f My present invention relates to t method and apparatus for forming conduits7 partic-V ularly' underground conduits having a plu,- ralityof ducts for carrying electric cables.

An object of the invention'is to provide a method and zippnratus for forming continuous `conduits in 'which cement or other plastic ijnuteriall is forced into position uniformly and with. a continuous, uniform pressure,

pervious conduit Wall.

Qther ebieete'ef the. .invention nre s 'ne pro.- vi'de a method and apparatus for forming Continuous Vconduits in which plastic mate; reinforced ne@ e) progressie-1y man@ mold by :i pressure which refacts to create a direct ,thrust in `the direction of movement thereby ensuring a uniformly dense and iinof the mold 'und to `id vauce the letter proporti'on'ately as 'the conduit construction 2idnnne-ee; n0- `isnlwnlein nnellllng menne that .enenree Sinn-enh, nnbreken lnnenef fen .elle

couduitg'to provide an apparatus invvhi'ch a' ielnrnln-y el ennelnne my be Simultaneously formed; land to providel a Simple, directectf ine mennen-.inn in Wlneli tne-.fer'eng nf' *Alle plastic `materiel and` advancement 'of the ymold 'in zty Lhe'gcconiplished with a minimum eX-V penditnre of'power.

'With these and ether Obi eene. in view, which 1 will. nppegr more indetnl'frem .the fQllW ing eles'erpten, .the invention eenlprieesl the iriethod lztndnpp arzitus de scrihedgnd s'etforth in the iellowing Veneefennen eneldenne- The -vglrimis features of the invention are in .the eeeeinpnnying drawing, .in which? Fig. .11s longitudinal seamen view of a conduit formi :ge machinei'enibodyin'g the .Fig '3 .ie n yertieel Sleeten teken onine line 3 3 of Fig. l.V y

Fig elle .end ,vien/nf the nnnefnlns teken trom the .advancing n.1 ,driving enel, n per- '.l-inn Enf. the "enel `well being fbrlnken nvny. ne .-lnere .e-lenrly. Show .the lnternn ennstrnennn. V- lnmy inyention, theconcrete or other plastic 'mnt'.erial :to be'l formed r.into g'jconduit is 5 'nleeesl in ,feeding le'ennnennent in. .nenn

nre nnelened ene er more dnee .forming @eres 0r {tinndfele' which' .extend-'from the fnnnt veelf eli 'the' .eelnpernnen'n 're'nrverlelly tlnfengn n eylnlle'nl 'feed Greening 'inte nn einen; ended, 'neerwnrdly' den'nee'd" melding enlnnnrnnenn' Eneh enne 'provided with' llelenl venne ennenlng/nhrengnthe feed. opening .nnd's r'o ated to 'force the plastic 11.1.21*

tennlfreni th'leed enambr tnriong'hthe feed 1 Opening 199,0' ,tlie molding 'enrnpnntlnenn ,When .fine melding cenlpnrtlnente lllefl'with nlnen'e' ngt-enel, 'lne' 'fnrtner e'tnten" of @ne lnnnelrelnr @gre inlle'ns'es' n preeenre On the dirent; lernten@ thrust en the' Coin-.eend its enpnentn'g nnnnrntneanld thereby, nnen the attainment 'et enlleent'nreenlfe, feeee the' entne' .lnellng' vln'nn@nenne frwnrelly? One .0.1" molte ,Cores ni" 'lnnndlele inny be' need' .t0

Pf Snell .Genesi .eine Slley'vn; by wey .f exemple, 1n the accompanying 1m-Wing l f Referring Inefe pnrlenlnfly winne eeeenn- Ennying ?nwing,`tl1e.eernenn0r eenere'te le supplied n? afmelding .apparatus fio through n.' nenne? .11,1nnd'inereeeiyel inn feeding compartment 12; The "compartment 12 is formedneeenqsn wenn ann 14 .ofthe Each 'ofthe cores17-20 1s encircled yvith ,apen of continuelle, nelenl ynnes'nrgidly vends ,ofthe nenes'. te .tlie'ey ndrenl 'pasengewnye 2h24! llpeln the materielsmugedunifo lytbbm-lfhe pres "vienne nenne n ist nnen by .ne

helical vanes 26 rearwardly through the passageways 21-24 into a molding compartment 27 at the rear of the feeding compartment 12. The molding compartment 27 is closed at its sides by the side walls 13 and 14, and at its top kby a cover vplate 28, the rear of the compartment being closed onlyby plastic material already formed and set in position, andthe bottom being closed by the surface on which the conduit is to be laid.v

As the plastic material is forced by the rotating helical vanes 26into the compartment 27, it completely fills the compartment. The further rotation of-the vanes serves to pack the material under pressure.V This pres` sure re-acts against the vanes 26,' causing a forward thrust on the cores 17-20, which is received by the front plate 15. j When this thrust becomes sufficient to overcome the Weight and resista-nce to movement of the molding apparatus, it causes the latter vto move forwardly', thus' permitting an addi# tional quantity ofy plastic material to bel forced into the compartment '27. As the vanes 26` are continuously rotated, the apparatus moves gradually1 and continuously forward luiderv there-action to continuous, uniform pressure on the plastic material. s

The diameter of the cylindrical passage` ways 17-20 is equalto the diameter ofthe outer edge of the vanes 2G, so that' the vanes and cores are -journalled and supported in the cylindrical passageways.- The cores are supported at theirV frontfends by means of journals 29 of'reduced'diameter, Vwhich eX- tend through bearings or bushings 30 in the front wall 15. i

*The cores 17-20 suitable means kthat will "ensureV a uniform,

simultaneous movement lof all ofthe cores.

In the embodiment shown in thelaccompany ing drawing, the motive power is supplied to a shaft 31, which is journalledv in a bearing 32 in a compartment 33 at the front end of the apparatus ,and is `providedwith a gear wheel' 34' which'meshes with'an internal gear immediately back, of the end of the shaft 31. The gear 35`is ycentered and Vsupported by a rearwardly extending yshaft 36, lhaving a gear 37 which is positioned centrally of, and meshes with, each of four gears 38,39, 40 and 41 secured on` the forwardly projecting ends of the journals 29 of the cores 17'-20, respectively.

It will be apparent that, upon the rotation of the shaft 31,. each ofthe 'gears 38-41 is ,simultaneously and uniformly rotatedin the same direction.

Through'the above invention the` plastic,

material is forced into position in a forwardly movable moldingcompartment un- Ader a uniform'and continuously acting pressure and the `reaction from this ,pressure serves directly to advancethe molding' ap-y paratus.V The rotation of the c'ores`17-2O lmayj'be rotated byl any ,f

has an additional advantage of forming a very smooth interior surface for the ducts and, as the principal movement is circular, the tendency for any portion of the material to fall or be dragged inwardly is thereby *f greatly reduced. To still Yfurther avoid any disturbance of the surface of the ducts by the rear edges of the cores, the ends of the cores are slightlyrounded. But` the ...unif

form diameter of cores is maintained prac-kv should be maintained practically `uniform tically to the end. Experience has shown that the pressure of the cores on the concrete throughout-the length of the core to prevent particles of concrete from being loosened from the face of the duct and falling into the latter, from whichit must be cleanedi out trench 44, which offers a frictional resistance proportional to the constant weight of the apparatus and tendsto secure uniformity "of movement. e

As changes of construction could be' made within the scope of my invention, it is intended that all matter contained in the above description' or shown inthe accompanying drawingshall be interpreted'as illustrative and not in a limiting sense.

Having now described my invention, what i t' I claim as new and desire to secure by Letters Patent is: 1.

e 1. Apparatus of the type described which comprises an open'ended bottomless mold, a

feed chamber forplastic material,a pluralityy offeed openings from` said feed chamber'to said open ended mold, a` plurality of cylindrical cores, one for each of said feed openings, extending from said feed chamber through lsaid feed openings intov said open ended mold, anda helicalV feed vane on each of said cores.

2. Apparatusfof the type described which comprises an open ended mold, a feed cham* `ber for plastic material, a plurality of tubular feed passages'from said feed chamber to said open ended mold, a plurality of cylindrical cores, one for eachof said'feed passages extending from said feed chamber through said feed passagesy into said open ended mold, a helical feed vaneon 4each of said cores, a

vdriving gear on each of said cores, and a com! mon driving means engaging each of said gears. j I

Y 3. Apparatus of the type described which comprises a longitudinally movable mold havi inga feed chamber for plastic material'in advance of said mold,a plurality of cylindrical passageways from said feed chamber to said l mold, cores centered one in each of'said pasl. sageways, means for continuously rotating said cores, and means reacting against said core for continuously feeding plastic material into said mold upon the rotation of said core, said apparatus having supporting skids which offer a substantially constant frictional resistance to its longitudinal movement.

4. Apparatus of the type described which comprises a pair of side walls and a cover plate forming an open ended open bottom mold chamber, a feed chamber in advance of said mold chamber, a plurality of cylindrical passages from said feed chamber to said mold chamber7 a plurality of cores, one for each of said cylindrical passages, extending through said feed chamber, said cylindrical passages and into said mold chamber, a pair of continuous helical vanes on yeach of said cores, the outer edges of said vanesV contacting with said cylindrical feed passages to support said cores, a trough in the lower part of said feed chamber forming and contacting with the edges of the lowermost of said helical vanes, and means in said feed chamber for simultaneously and uniformly rotating said cores.

5. Apparatus forl forming continuous conduits which comprises a feed compartment for Vplastic material, feed passages from said compartment, rotating cores projecting from said compartment through said feed passages, means for continuously feeding plastic material from said compartment through said passages about said cores, and open ended means for conning said plastic material on the ground immediately at the outlet of said feed passages.

6. `Apparatus of the type described which comprises a longitudinally movablebottomkless mould having a feed chamber for plastic material, a horizontal cylindrical core extend-V ing from said feed chamber into said mould and means for forcing plastic material from said feed chamber longitudinally about said core into said mould.

7. Apparatus of the type described which comprises a. longitudinally movablel bottomless mould havingV an open end, a feed cha-mber for plastic material, a horizontal cylindrical core extending from said feed chamber into said mould'and means for continuously forcing plastic material from said feed chamber longitudinally about said core'into said mould.

8. Apparatus of the type described which comprises a longitudinally movable bottomless mould having an open end, a feed chamber for plastic material, a cylindrical rotatable horizontal core extending from said feed chamber into said mould and toward its open end, means for rotating said core and means ber and said mold, a rotatable cylindrical core extending from said feed chamber through said cylindrical passageway into said mold and having a helical vane fixed thereto within said cylindrical passageway.

l0. A method of forming conduits in a massV of plastic material, which comprises forcing said plastic material from a supply mass thereof through separate cylindrical passageways, one for each conduit, and uniting and confining the material k thus forced through said separate passageways in a common mass,

holding stationary at least part of its surface and against which said material forced through said passageways reacts.

In witness whereof, I have hereunto signedk my name.

` JOHN F. MURRAY.

for forcing plastic material longitudinally l about said core from said feed chamber into said mould.

9. Apparatus of the type described which i' iso 

